Interactive input systems that allow users to inject input (eg. digital ink, mouse events etc.) into an application program using an active pointer (eg. a pointer that emits light, sound or other signal), a passive pointer (eg. a finger, cylinder or other suitable object) or other suitable input device such as for example, a mouse or trackball, are known. These interactive input systems include but are not limited to: touch systems comprising touch panels employing analog resistive or machine vision technology to register pointer input such as those disclosed in U.S. Pat. Nos. 5,448,263; 6,141,000; 6,337,681; 6,747,636; 6,803,906; 7,232,986; 7,236,162; and 7,274,356 and in U.S. Patent Application Publication No. 2004/0179001, all assigned to SMART Technologies ULC of Calgary, Alberta, Canada, assignee of the subject application, the entire disclosures of which are incorporated by reference; touch systems comprising touch panels employing electromagnetic, capacitive, acoustic or other technologies to register pointer input; tablet and laptop personal computers (PCs); smartphones, personal digital assistants (PDAs) and other handheld devices; and other similar devices.
Above-incorporated U.S. Pat. No. 6,803,906 to Morrison et al. discloses a touch system that employs machine vision to detect pointer interaction with a touch surface on which a computer-generated image is presented. A rectangular bezel or frame surrounds the touch surface and supports imaging devices in the form of digital cameras at its corners. The digital cameras have overlapping fields of view that encompass and look generally across the touch surface. The digital cameras acquire images looking across the touch surface from different vantages and generate image data. Image data acquired by the digital cameras is processed by on-board digital signal processors to determine if a pointer exists in the captured image data. When it is determined that a pointer exists in the captured image data, the digital signal processors convey pointer characteristic data to a master controller, which in turn processes the pointer characteristic data to determine the location of the pointer in (x,y) coordinates relative to the touch surface using triangulation. The pointer coordinates are conveyed to a computer executing one or more application programs. The computer uses the pointer coordinates to update the computer-generated image that is presented on the touch surface. Pointer contacts on the touch surface can therefore be recorded as writing or drawing or used to control execution of application programs executed by the computer.
In some interactive input systems, conventional projection units are employed to project a computer-generated image onto a surface with which a user interacts. For example, U.S. Pat. No. 6,540,366 to Keenan et al., assigned to SMART Technologies ULC, discloses an overhead projection system comprising an overhead projector support assembly extending generally horizontally from a generally vertical support surface. A touch-sensitive display screen having a display surface is mounted on the support surface beneath the projector support assembly. A projector is mounted on the projector support assembly adjacent to its distal end and is aimed to project images onto the display surface of the touch-sensitive display screen. The touch-sensitive display screen outputs control signals in response to contacts made thereon. The control signals are then conveyed to a personal computer, which uses the control signals to update the application program being executed and to update the image projected onto the touch-sensitive display surface by the projector.
U.S. Pat. No. 6,281,878 to Montellese discloses an input device for detecting input with respect to a reference plane. The input device includes a light source, a light sensor and a processor. The light source provides a plane of light adjacent to a reference plane, such as a solid surface of a desktop, on which an input template image of a keyboard is projected by a projector. The light sensor having an acute angle with respect to the reference plane, senses light reflected by an object, such as a finger close to the plane of light and generates a signal indicative of sensed light. The processor determines a position of the object with respect to the reference plane based on response of the sensor.
U.S. Pat. No. 7,268,774 to Pittel et al. discloses a writing instrument and a method of tracking motion of the writing instrument. Light emitted by the writing instrument is detected by two spaced sensors clipped to the edge of a writing surface such as a piece of paper. Locations of the moving writing instrument are determined based on the sensor signals and stored in the writing instrument. Handwriting is then automatically reconstructed when the stored information is downloaded into a computer.
U.S. Pat. No. 7,307,661 to Lieberman et al. discloses an electronic camera including an imaging sensor. In one embodiment, the electronic camera includes a projection subsystem for projecting an image of a keyboard on a projection surface such as a desktop and an illumination subsystem for directing an illumination pattern parallel to the projection surface. Light scattered or reflected by a data entry object, such as a user's finger, a stylus or other implement close to the keyboard is detected by the imaging sensor. Location of the data entry object is determined by a detection subsystem employing the imaging sensor and is used to indicate which key of the keyboard is being engaged.
U.S. Patent Application Publication No. 2011/0242054 to Tsu discloses a projection system including an image projector, an invisible light transmitter and an invisible light sensor. The image projector is used for projecting a projection image on a physical plane. The invisible light transmitter is used for generating an invisible light plane, which is parallel with the physical plane. The invisible light sensor is in communication with the image projector. When a pointing object is placed on a touching point, an invisible light beam reflected from the pointing object is received by the invisible light sensor. According to the invisible light beam, a sensing signal indicative of a spatial coordinate position of the touching point is acquired and transmitted to the image projector. The image projector recognizes and calculates the spatial coordinate position of the touching point according to the sensing signal and performs a controlling action according to the spatial coordinate position.
Chinese Patent Application No. CN201110336523A to Dai et al. discloses a virtual electronic whiteboard device that includes a linear light source and an image information processing device. The linear light source is provided with a camera and is placed at a display surface such that the light emitted by the light source forms a light touch surface and is parallel to, and infinitely close but without touching the display plane. Images captured by the camera are processed by the image information processing device. When light of the light touch surface is blocked by a touch object to form a touch point, the information processing device processes the images obtained by the camera and determines the position and state of the touch point.
Adjustable light sources have also been developed for many optical devices such as for example laser printers and facsimile machines. For example, U.S. Patent Application Publication No. 2007/0086085 to Kitaoka et al. discloses a light source apparatus that includes a light source unit in which a light source and a light source supporting member having elasticity in an optical axis direction are coupled together, and a collimating lens base member on which a collimating lens is supported. An optical axis direction adjusting member is positioned between the light source unit and the collimating lens base member. A position of the light source unit can be adjusted within a plane approximately perpendicular to the optical axis, and the light source unit can thereafter be secured relative to the collimating lens base member via the light source supporting member. The optical axis direction adjusting member is movable in the optical axis direction, and is disposed such that by its movement it causes the light source supporting member to deform against the elasticity of the light source supporting member, thereby allowing an adjustment of a position of the light source with respect to the collimating lens in the optical axis direction.
Although many different types of interactive input systems exist, improvements are continually being sought. It is therefore an object of the present invention to provide a novel interactive input system and method.